JP GMR 15 lower?

[RandyBaker]

I have a JP GMR15 lower and short stroke BCG. Will any 9mm upper work this? 
I searched and couldn’t find the answer.

Thanks

[Darqusoull13]

For the most part if it's a standard AR pattern yes. Bolts will need central weights removed if solid / non-JP. 

 

Best advice is to just get a JP upper though. 

[RandyBaker]

16 minutes ago, Darqusoull13 said:

For the most part if it's a standard AR pattern yes. Bolts will need central weights removed if solid / non-JP. 

 

Best advice is to just get a JP upper though. 

Thanks for the reply. The only reason for not wanting a JP upper is I was wanting just a cheaper 9mm upper to play with. 
 

since I have the JP BCG that will still work in other uppers...is that correct?

 

thanks again

[Silverscooby27]

I have a Foxtrot Mike upper that I use from time to time with a GMR-15 lower and it works great.

[CharlieD]

If the barrel has an extended feed ramp it may not fit due to the LRBHO on the JP.

[Darqusoull13]

7 hours ago, RandyBaker said:

Thanks for the reply. The only reason for not wanting a JP upper is I was wanting just a cheaper 9mm upper to play with. 
 

since I have the JP BCG that will still work in other uppers...is that correct?

 

thanks again

Correct as long as they are "mil spec" AR15 pattern. I built a bunch of uppers with JP guts off standard AR uppers.

[RandyBaker]

Thank you all for the responses

[kellymc]

I tried a taccom upper on a GMR 13 and the mag sat to high for the taccom bolt. 

Edited June 9, 2020 by kellymc

[Sniperboy]

On 6/9/2020 at 4:14 AM, kellymc said:

I tried a taccom upper on a GMR 13 and the mag sat to high for the taccom bolt. 

 

I have had this experience too with my GMR13.  I can't comment on other brands of bolts, but unless you can try ahead of time it may be safer to buy a JP bolt if you have a JP lower.

[kellymc]

I went ahead and built a QC lower for my taccom 5/16 upper. Seems to work fine and I leaving my GMR 13 intact